<!DOCTYPE HTML>
<html xmlns:th="http://www.thymeleaf.org">
<head>
    <title>HelloWorld</title>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
</head>
<body>
<button onclick="this.disabled=this.disabled?false:true">aaaaa</button>
<span th:text="${demo.id}"></span>
<span th:text="${demo.username}"></span>
<span th:text="${demo.address}"></span>
<a href="../buyer/buyer_center.html" th:href="@{/product/product_details(id=${demo.id})}" >aaa</a>
</body>
</html>